Duplex spring sash balance



Dec. 15, 1931. F, ANTi 1,836,080

DUPLEX SPRING BALANCE Filed July 25, 1928 Patented Dec. 15, 1931 PATENT; OFFICE ALOYSIUS F. EANTZ, 015 LOS ANGELES, CIJI'OBNIA.

nurmax srnme sass saunter:

Application filed m as, 1928. Serial No. 295,184.

- My invention relates to a duplex spring sash balance, and the construction herein described and claimed is an improvement on the sash spring balance forming the subjectmatter of United States Letters Patent No. 1,669,990 issued to me May 15, 1928.

The principal objects of my present invention are to generally improve upon and simplify the construction of the spring sash balance covered by my aforesaid patent, as well as other similar forms of spring sash balances, further to provide a sash balance of the character referred to that includes a double or duplex spring so as to materially increase the capacity of the device insofar as the weight of the associated sash is concerned, and further and practical duplex spring sash balance that is entirely automatic in operation and capable of being readily installed or removed and replaced 'n order to facilitate adjustments or repairs.

A further object of my invention is to provide a duplex sprin sash balance that occupies an opening in t e jamb or upright side member of the window frame and said balance and its housing lyin in a plane parallel with the plane occupied by the jamb or upright side member of the window frame.

A further object of my invention is to provide simple and eflicient means for producing frictional resistance between the cable-carrying drums or spools and the housing of the device, and which frictional resistance results in the maintenance of minimum tension in the spring and the sash that are connected, said sash remaining stationary in all positions without creeping as a result of pulling strains produced by the spring.

With the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts that will hereinafter be more fully described and claimed and illustrated in the apc'ompanying drawings, in which:

to provide a relatively simple Fig. 1 is an elevational view of a duplex spring sash balance constructed in accordance with my invention with portions of the cable carrying drums broken away.

Fig. 2 is a vertical section taken on the line 2-2 of Fig. 1.

Fig. 3 is an edge view of the housing or casing that encloses the operating parts of my improved duplex spring sash balance. Fig. 4 is a vertical section taken through the center of the housing or casing and showin the duplex spring arranged therein.

5 is a vertical section showing a modii fied orm of the drum tensiomng means.

Referring by numerals to the accompanying drawings which illustrate a practical embodiment of my invention, 10 designates a shallow pan-shaped member preferably formed of pressed sheet metal and proj'ectin outwardly from the upper edges of the en walls of said member are narrow flanges 11 that are perforated for the reception of small nails or the like that are utilized in securing the member 10 to the window jamb. ThlS member 10 forms the main body of the hous 7 ing or casing for the sash balance and said housing is rovided with a front wall or plate 12, preferably formed of sheet metal, and its edges are connected to the side and end walls of the housing member 10 by lips or tongues 13 that are formed integral with the edges of the front cover plate 12 and which pass through suitably located apertures in the side and end walls of the housing member 10.

Formed in the upper and lower portions of the rear wall of housing member 10 and in the corresponding portions of cover plate 12 are openings that provide bearings for the tubular hubs 1 1 of the cable-carrying drums, 85 said tubular hubs extending a short distance forwardly from the cover member 12, and secured in any suitable manner to the forwardly projecting portions of said hubs are spools or drums 15, each composed of a pair of disks, 1

means of small I the outer portions of which are spaced apart a sufficient distance to accommodate the metal cables 16 that form a flexible connection between the sash balance and the window sash.

Arranged in the bottom of the space between the outer portions of each pair of disks 15 is a narrow ClIClllflIbaIld or plate 17 that provides a flat bottom for the chamber or space that receives the cable 16, and the portions of the disk, beyond 'thlS bottom plate 17 are spaced a sufficient distance apart for the cable to wind upon itself in a single row of coils or convolutions. 1

It will be understood that one cable 16 is carried by the upper one of the two drums and a separate cable is carried by the lower one of the two drums. The cables are wound onto the drums in different directions so that the outer end of the upper cable is disposed adjacent to one side of the housin of the sash balance while the outer end of t e lower cable is disposed adjacent to the outer side of said housing.

The outerends of both cables are provided with suitable hooks, such as 18, that are connected respectivel to the edges of the upright side rails o the window sash.

Secured in any suitable manner to the rear ends of the tubular hubs 14 that carry the cable carrying drums and bearing against the outer face of the side wall of housing member 10 are disks 19.

Arranged on the tubular hubs 14 and positioned in the space between the cover plate 12 and the central portions .of the drums 15 are disk-like friction producing springs 20, the central portions of the bodies of which bear against the inner faces of the drums 15 adj acent to the tubular hubs 14, and formed integral with the outer portions ofthese disks 20 are radially disposed curved resilient fingers 21 that bear on the outer surface of the front cover plate 12. These disk-shaped springs produce frictional resistance between the cable carrying drums and the front cover plate of the housing, thereby producing yieldmg resistance to the action of the spiral springs and holding the sameagainst movement that would otherwise cause creeping of the sash when the latter are moved into open orpartially open positions.

rranged in the chamber within the hous-- ing is a duplex spring, that is a spring formed from a single piece of material, preferably flat steel tape that is wound to form two' spiral springs 22, theconvolutions of which are oppositely arranged and the inner ends of these springs are connected respectively to the tubular hubs 14, as illustrated in Fig. 4.

Formed through each drum just inside the bottom plate 17 is a small aperture 23' and formed through the front cover plate 12 and through the bottom wall of the housing member 10, are alined apertures 24, and which apertures 23 and 24 are adapted to receive a pin or key to hold the drum against rotation while the cable is being wound thereonto during the installation of the sash balance or during the adjustment of the tension of the spiral springs. v

Instead of forming the two springs 22 from a single piece of resilient metal tape, as illustrated, it may be desirable in some instances to utilize two separate springs, in which event the outer ends of the springs Will be secured in any suitable manner to the housing of the device.

When my improved spring sash balance is installed for use a substantially rectangular opening is formed in the amb of the window. frame, which opening is of suflicient size to accommodate the housing, and the latter is set into said opening with the end flanges 11 bearing on the face of the jamb and said housing is secured to the jamb by small nails or like fastening devices that are driven through apertures in the flanges 11 and into the jamb above and below the opening therein.

Thus the housing occupies the opening in the jamb and the duplex spring occupies a plan]: parallel with the plane occupied by said am J The book 18 that is connected to the cable carried by the upper one of the drums is secured to the adjacent side rail of the upper sash, and in like manner the hook 18 that is carried by the cable on the lower one of the dllilms is secured to the side rail of the lower sas springs 22 are partially coiled or wound so as to produce a certain degreeof tension, and which tension while tending to raise the lower sash and pull the upper sash downward, is insufficientto move eitherv one of the sash due to the Weight thereof and to the frictional engagement between the stiles of the sash and the window frameincluding the j ambs, parting strips and stops.

To partially wind the springs so as to produce tension therein, each drum is manually rotated a few turns so as to partially wind up When the sash balance is installed the spiral the corresponding spring, after which a pin i or nail is inserted through the alined apertures 23 and 24 and the corresponding cable is now wound upon the drum until the hook 18 is adjacent to the periphery of the drum.

The hooks 18 are now secured to the stiles of yieldingly support the sash in both open and .closed, and thus both sash are at all times firmly supported in the window frame and at the same time it is possible to easily raise and lower the sash due to the yielding and resilient support afforded by the spiral springs that are connected to the hubs of the cable carryin drums.

In the mo ified construction illustrated in Fig. 5, a friction disk 25, carrying a series of radially disposed fingers 26, is arranged against the outer said frict'on disk being retained in position by a screw 27 the threaded end of which passes through a disk 28 that is secured in the inner end of the tubular hub 14a.

This friction disk 25 performs the same functions as the friction disk 20 and the screw 27 provides simple and eflicient means for adjusting the 'tensionor frictional resistance that is produced by the friction disk upon the cable carrying drum.

Thus it will be seen that I have provided a spring sash balance that is relatively simple in construction, inexpensive of manufacture, practically noiseless in operation, ca:

pable of being readily assembled and installed and said spring balance being very effective in performing the functions .for which it is intended,

It will be understood that minor changes in thesize, form and construction of the various parts of my improved duplex spring sash balance maybe made and substituted for those herein shown and described withoutdeparting from the spirit of the invention, the scope of which is set forth in the appended claims.

I claim as my invention:

1. In a spring sash balance, a pair of cablecarrying drums mounted for independent rotary motion and having independent axes, flexible members connected to said drums and adapted to wind thereonto, which flexible members are adapted to be connected'to window sash, and a spirally wound spring having its end portions connected respectively to .said drums.

2. In a spring sash balance, a housing having a removable front wall that is inset with respect to the ed es of the side walls of the housing so as to orm a shallow recess in the front of the housing, hubs journaled in the front and rear walls of the housing, drums carried by the forward ends of said hubs and positioned in the recess in the front of said housing, said drums being disposed one above the other, flexible members connected face of each drumq15, and

to and adapted to wind upon said drums, the space between the flanges of the drums being slightly greater than the diameter of the flexible mem ers so that the convolutions of said flexible members on said drums are positioned one directly. upon the other and a spirally wound sprlng having its end portions connected respectively to the hubs of said drums.

In testimony whereof I affix my signature.

ALOYSIUS F. MANTZ. 

